Superionic effect and anisotropic texture in Earth's inner core driven by geomagnetic field.

Seismological observations suggest that Earth's inner core (IC) is heterogeneous and anisotropic. Increasing seismological observations make the understanding of the mineralogy and mechanism for the complex IC texture extremely challenging, and the driving force for the anisotropic texture remains unclear. Under IC conditions, hydrogen becomes highly diffusive like liquid in the hexagonal-close-packed (hcp) solid Fe lattice, which is known as the superionic state.

Superionic iron alloys and their seismic velocities in Earth's inner core.

Earth's inner core (IC) is less dense than pure iron, indicating the existence of light elements within it. Silicon, sulfur, carbon, oxygen and hydrogen have been suggested to be the candidates, and the properties of iron-light-element alloys have been studied to constrain the IC composition. Light elements have a substantial influence on the seismic velocities, the melting temperatures and the thermal conductivities of iron alloys.